<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #d1 {
            width: 200px;
            height: 200px;
            border: 10px solid #151515;
            border-radius: 50%;
        }

        #d2 {
            width: 100px;
            height: 100px;
            border: 1px solid rebeccapurple;
            padding-left: 50px;
            box-sizing: border-box;
        }
    </style>
</head>

<body>
    <div id="d2">内边距</div>
    <div id="d1">边框测试</div>
</body>

</html>